342 Fatigue

Fatigue resistance for a particular detail is the allowable constant-amplitude stress range (S) for a specified number of cycles of loading (N), typically expressed in an S-N curve. S-N curves are based on fatigue tests of full-scale members with welded or bolted details. The assignment of various details to specific categories for S-N curve analysis is discussed below, including bolts, anchor rods, hollow structural sections, concrete members, and cables.

When information about a specific crack is available, a fracture mechanics crack growth rate analysis should be used to calculate the remaining life [3,4]. However, in the design stage, without specific initial crack size data, the fracture mechanics approach is not any more accurate than the S-N curve approach [5]. Therefore, the fracture mechanics crack growth analysis will not be discussed further.